1. Technological Field
This technology pertains generally to image coding, and more particularly to an apparatus and method for utilizing intra and inter-plane prediction during RGB image coding.
2. Technological Background
A RGB color model comprises red (R), green (G) and blue (B) in this additive color model in which R, G and B are added in various amounts toward reproducing a desired color in its spectrum. The RGB model is extensively utilized in various electronic image systems, in particular televisions and computers, although it is also utilized in some instances for digital photography. In the RGB model, zero intensity for each color component yields black, while full intensity for each results in a white. Although the quality of the white light, in relation to true white, depends on the nature of the primary RGB light sources. Each of the RGB colors is quantized to a desired color depth which is expressed as a number of bits, such as from 1 to 24 bits or more, although most typically 8 to 24 bits, depending on the application and its attendant need for color accuracy.
FIG. 1 depicts the three color planes in RGB coding. By way of example, only 8 pixel groups are seen, R1-R8, G1-G8, and B1-B8, for the sake of convenience of illustration.
Conventional RGB encoding utilizes a combination of pulse code modulation (PCM) and differential pulse code modulation (DPCM) when encoding an RGB image block. In some encoding systems, predictions are performed based on intra-plane correlations, toward increasing coding efficiency. However, it would be beneficial to enhance RGB color encoding to further increase coding efficiency.
Accordingly, the present technology provides additional RGB coding benefits and overcomes shortcomings of previous approaches.